Is pre-bend so important? Now the boom is straight and not under very much tension. I always thought, that when you pull the mainsheet, there will be extra tension on the boom, which should be enough....
Pre-bend on the spinnaker pole is important to avoid breaking the pole, and to keep it fixed. With some pre-bend, the loads from the kite put the pole into compression and the tip of the pole is well braced.
Paul
